Please help a young adult out

Patient

Q:Hi i have a serious problems when i masturbate i don't use my hands i use my legs and rubbed it against my penis to shoot out sperm and i have been doing that since i was 7 years old til now I'm 21 years old and now i stop doing it but each time when i used my legs to rubbed it against my penis i crushed my penis and ballsack how do i get my penis and ballsack back to normal? Also I would like to have kids in the future with my girlfriend please help me out.

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